NBA salaries of U-M alums

Plus--at least in the private sector compared to government jobs-- how much they earn is a direct reflection of how much worth they're providing the marketplace.  The salary isn't determined by any one individual--it's a collective deicsion we make as a society.  The reason an athlete or entertain can make X millions of dollars per year is because they're worth more than that in terms of value to either team owners, ticket/event promoters, corporate sponsors, etc.  And the reason the team owners, event promotors, corporate sponsors, etc. decide those athletes and entertainers are worth it is because collectively we as a society prove over the course of years that it IS worth it--when they hire XYZ actor or athlete, we collectively are willing to pay those millions by being entertained by those actors or athletes or when they do celebrity of endorsements we  collectively buy more of that product.  

Granted, some entertainers and athletes are underpaid--in which case you would think eventually the marketplace (and the athlete/entertainer themself) would figure that out and boost their income.  And conversely, if somebody is OVERPAID for their performance, eventualy the marketplace will figure that out too.  And it even has only tangental relationship to how HARD somebody works.  It plays a part in a competitve marketplace since it's likely to boost the skill or ability of the person who is working hard.  But it's not always the case.  Somebody could work 24/7 making buggy whips, but if nobody drives buggy & horse carriages anymore, that guy is going to go broke.  Or somebody could be naturally gifted and not have to work hard to provide alot of value.

Bottom line is, barring theft or fraud, it has everything to do with how much collective value they're providing the rest of the marketplace.  Simple supply & demand.